Conventionally, driving characteristics (i.e., habits) of a driver are detected (i.e., specified), and a route is searched in accordance with the driving characteristics.
For example, JP-A-2008-107155 teaches technique such that driving information is collected in each link according to signals from various sensors such as an acceleration sensor, a brake sensor and a vehicle speed sensor, and the driving characteristics of a driver of the vehicle in an object link is specified based on the driving information. Further, a fuel cost is calculated according to the specified driving characteristics, and the route is searched so as to minimize a total of the fuel cost.
JP-A-2009-31046 teaches technique such that driving condition information and fuel consumption information including vehicle information such as vehicle speed are obtained in unit driving section such as in each 1-kilometer driving section. Multiple past driving condition patterns are preliminary stored, and one of the past driving condition patterns, which has strong correlation with current driving condition information and fuel consumption information, is determined. Then, a fuel consumption distribution data corresponding to the determined past driving condition pattern is updated. Further, the fuel consumption distribution data is utilized for fuel consumption calculation and cost calculation in a route search process.
However, in the above technique, since the driving characteristics are specified according to the driving information in each section having a predetermined distance or each link, the driving characteristics are not specified in each driver with high accuracy.
Specifically, in an individual link or an individual section having the predetermined distance, a factor for limiting traffic of the vehicle such as a temporally stop place and a traffic light may exist in a random manner. The factor for limiting traffic is defined as traffic limitation factor. Thus, the driving information relating to the vehicle speed and vehicle acceleration in the individual link or the individual section may be varied because of the traffic limitation factor. Further, even in the same link or the same section, the traffic limitation factor is changed in accordance with time. For example, the traffic limitation factor depends on a status of the traffic light such as a red signal or a blue signal. Thus, the driving information relating to the vehicle speed and vehicle acceleration in the individual link or the individual section may be varied with time. Accordingly, when the driving characteristics are specified according to the driving information in each link or each section having the predetermined distance, the driving characteristics of each driver are not specified with high accuracy.